Why do all my sprues tear?

[5Shot]

Doesn't seem to matter how long I let it cool (and I have let a mold cool completely before cutting) they always tear to some degree. I have tried a fan, speed cooling with a damp rag and good old fashioned waiting. The mold is an Applegate, and the tool steel sprue plate seems very sharp. I use a fairly heavy rawhide mallet and cut them in one solid tap. I have also tried just pushing the plate open and many lighter taps...nothing seems to give me that perfectly smooth cut that you read about.

I am using WW + 2% and run the melt fairly hot. I am using a Rowel ladle to pour.

Any thoughts? I am by no means an experience caster...I just piddle around now and then to cast what I need.




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In addition, and possibly related, I still see quite a few bullets (maybe as high as 50%) with small rough surfaces that look like the pictures I have seen of "Dirt". I however have scrubbed the bajeezus out of the cavities with soap and a toothbrush, degreased with MEK and then smoked them when that didn't seem to eliminate the issue. I have fluxed with pretty much everything - commercial flux from Bill Ferguson, Paraffin, Bees Wax and Wood Chips (I used newspaper, but figured I was still getting the carbon). Nothing seems to help this. Everything is filled out perfectly, so I don't think it is a contaminate in the melt. I am careful to make sure the spout of the ladle is free of dross before pouring, but it doesn't seem to make any difference. It looks to be more cosmetic than anything, but it is still frustrating. When I get things really cooking and the bullets are all frosted I don't see it any more (I am sure it is still there), but since I don't see it, I like frosty bullets more!

Seeing perfectly cast bullets on here just pisses me off, cause I can't make it happen!

On this one you can see the "Dirt" on the two bullets on the right. Very faint (and impossible to photograph), but it is there none the less.

[Char-Gar]

The best molds ever made were by Rob Applegate and everything you are doing sounds correct. I am left to believe you either have expectations that are not realistic, some kind of funky alloy or too small a spru.

My best bet is unrealistic expectations. Post some pictures of your bullet bases and we can tell you to relax or if you have a problem. Always remember that folks (including myself) post pictures to brag a little. This means folks show their best groups and prettiest bullets.

[leadman]

Are you using clip on wheel weights, stick on wheel weights, or a combo of both? The reason I ask is that 2% is good most of the time with clip on ww, but not enough for stick on or combo.
How many times do you flux the pot before casting? Newspaper might cause some of this dirt you are seeing, along with any coated boolits added to the pot.
I usually flux at least 3 times with beeswax, then once with candle wax before casting.
A small tear from a base usually does no harm. I did a test with my very accurate scoped Ruger BH Hunter in 41 mag and could not tell any difference from perfect base, small tear, and a large tear.
Pictures will help.

[Ben]

( 1 )Mold can be too hot, alloy can be too hot.
( 2 )Wait time prior to opening the sprue plate isn't long enough.
( 3 )The sprue plate could have an improper radius milled into the plate tearing the sprue, rather than cutting the sprue.

[tomme boy]

Most pictures of the boolits on here have been polished up with a cloth. Everything you are doing sounds good. Polish a couple up if you want to have pretty boolits.

[62chevy]

My bases look about the same and shoot very well. I find if the wait is to long then they tend to break leaving a jagged edge.

[OuchHot!]

The 'dirt' that you see may be dendritic crystal growth of antimony or one of its intermetallics. You might break this up with a bit more tin, but it doesn't look to me like something I would worry about. A faster cooling rate can sometimes reduce this. The sprue cut off is not too bad in my view but it is hard to judge from the photo. How do they shoot?

[fredj338]

Flux your alloy often, at least stir the pot with a wooden stick, often. This seems to eliminate a lot of the "flaws" that look like dirt. Shearing, could be too much antimony, it happens, fluxing often seems to help with that too.

[5Shot]

Are you using clip on wheel weights, stick on wheel weights, or a combo of both? The reason I ask is that 2% is good most of the time with clip on ww, but not enough for stick on or combo.
How many times do you flux the pot before casting? Newspaper might cause some of this dirt you are seeing, along with any coated boolits added to the pot.
I usually flux at least 3 times with beeswax, then once with candle wax before casting.
A small tear from a base usually does no harm. I did a test with my very accurate scoped Ruger BH Hunter in 41 mag and could not tell any difference from perfect base, small tear, and a large tear.
Pictures will help.

All clip ons...I set all the stick on ones aside.

I only flux once prior to casting, just to get the tin/dross combined back into the melt. Should I be fluxing multiple times, EVERY time? I just assumed that once I had added the wax or whatever that it would be ready to go and ready to go the next time. What does fluxing several times accomplish? I flux again, during the casting session, when the top of the melt starts to look like cottage cheese

How do they shoot?

I am heading out for a bit of serious group shooting this weekend - I will let you know how this last batch performs. Groups have been decent in the past, but nothing to really get excited about. Of course, I am shooting these in a 5 Shot Bisley Conversion, full throttle, so much of that could be me.

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One other thought I had - could some of the surface imperfection be due to the soft bullet hitting the folded up T-Shirt when it comes out of the mold? The landing surface gets little bits of lead on it over time...

[Shuz]

I recently had the same problem of sprue tearing on a fine old Saeco 441 4C mould. I solved the problem by sanding the underside of the sprue plate on a piece of glass that had 200 grit wet or dry sandpaper first, and then finished off with fine emery cloth.

[Char-Gar]

You are good to go. Looks like most of my bases. They will improve bit over time.

[Tar Heel]

I think they look fine. I doubt the moose you shoot will agree.

[Wayne Smith]

Are you using a bottom pour or a ladle? If a bottom pour you can put a layer of cat litter on your pot and keep O2 off. The wax flux returns oxidized metal back to it's elemental state, keeping O2 off the surface accomplishes the same thing in a different way. If you are ladle pouring you add O2 to the mix every time you use your ladle. This increases the oxidized metal floating on your lead and needs to be fluxed back in frequently.

[dubber123]

You apparently are way more serious about this than me.. The pictured boolits look fine, and the edges on the base of the first one is very sharp. If all mine looked like that, I would be a happy camper. I generally shoot 25 and 50 yds. My "crappier than your boolits" regularly produce 1/2" clusters at 50 yds from several rifles, and my last handgun group at 26 yards measured .48" for 5 shots. If you require better than that, by all means, keep tinkering

[Gtek]

Pot temp- did not see? Sprue size? Any noticable center draw before freeze in sprue? Appears to have sharp bases and grooves, just for fun have you cleaned up everything and tried another source of lead (not anything related to this source batch) ? You are aware of the evil clip ons that sneak into a hot pot? Maybe a little hard on yourself, I bet they shoot fine if right for pipe/application. Oh, and welcome to the madness!

[5Shot]

You apparently are way more serious about this than me.. The pictured boolits look fine, and the edges on the base of the first one is very sharp. If all mine looked like that, I would be a happy camper. I generally shoot 25 and 50 yds. My "crappier than your boolits" regularly produce 1/2" clusters at 50 yds from several rifles, and my last handgun group at 26 yards measured .48" for 5 shots. If you require better than that, by all means, keep tinkering

I like this reply...makes me feel like everything is all right in the world!

As far as pot temp - close to 750 per my Pyrometer. I was having some problems with fill out on the driving bands so I upped it a bit. Anything that was shiny or painted didn't go anywhere near the melt when I was putting up ingots. No center draw on cooling...I pour for a good second after the bump to make sure I have plenty at the base and I leave a good size sprue.

[labradigger1]

Most pictures of the boolits on here have been polished up with a cloth. Everything you are doing sounds good. Polish a couple up if you want to have pretty boolits.

You can polish boolits?
Why would you polish them?
If you have good temp, good alloy, good rythm and the stars line up just right all is good.
Lab

[TenTea]

We do the best we can and it appears you (OP) are doing better than many if not most.

Keep up the good work and relax...your bullets look excellent!

[5Shot]

I guess I just need to take a break, have a beer and relax a little!

[Bullwolf]

Just remember the pretty boolits don't shoot any better than the dull looking ones.

Sometimes the ugly ones actually shoot better than the shiny ones. None of them look so pretty after rolling around in Alox or 45-45-10 either.

My 2 cents, if I want a beautiful easy casting boolit, I will cast using straight Linotype.

If I want a shooter, I will cast from of a much softer batch of diluted alloy, and consequently the boolits look more dull.

Here's a Tub of 250+ boolits I recently cast from straight Linotype. (not polished)




The same front boolit after polishing the pink tint away with a paper towel, up close.


I can see the boolit shape, design, and flaws much better zoomed in on the PC screen, than I can using my old naked eyeballs.

Betcha that an uglier looking boolit, cast from a softer Alloy will give better me performance. If I want to see how a mould will cast (and the largest diameter I can get from it) and not jump through hoops or hassles, I just cast a batch with straight Lino.

High tin Alloys look prettier, and aren't as prone to oxidization. Doesn't mean they are any better, and in some cases they can be hard enough to be overly brittle. They do seem to photograph nicer though.



- Bullwolf